1. Field of the Invention
The present invention relates to a particle beam therapy system and a radiation therapy system utilized in the medical and R&D fields and particularly to a driving type patient platform, a control device for the driving type patient platform, and a control program for the driving type patient platform.
2. Description of the Related Art
To date, with the development of medical apparatuses and the advancement of medicine, medical apparatuses have been sophisticated and there have been emerging the types of medical apparatuses, which have not been seen before. For example, to date, the treatment through surgery, medication and/or radiation has been dominant in the cancer treatment; however, recently, much attention has been attracted by a particle beam therapy system that performs treatment by irradiating a particle beam exemplified by a proton beam or a carbon beam. The greatest characteristic of the treatment through a particle beam therapy system is that it is low-invasive, whereby the after-therapy QOL (Quality of Life) of a patient can be maintained. At present, particle beam therapy systems are working or under construction at approximately 10 facilities in total in Japan; some of the facilities are reportedly treating as many as 1,000 patients a year.
Accordingly, with regard to a bed, a chair, or the like (hereinafter, referred to as a “patient platform”) on which a patient is situated when undergoing a particle beam therapy, a function suitable for particle beam therapy is required; in addition, it leads to the contribution to the growth of the medical apparatus industry to develop a patient platform having a function suitable for particle beam therapy so as to produce a better medical apparatus.
Speaking briefly, a particle beam therapy system irradiates a particle beam in a pinpoint manner in accordance with the shape of a diseased site. For that purpose, it is required that the doctor or engineer (referred to as a “engineer or the like”, hereinafter) who operates the particle beam therapy system has to perform the work in which, assuming that the isocenter, which is an irradiation center, is a reference position, the position and the posture of the diseased site is made to coincide with planned values, i.e., the positioning work so that a particle beam can be irradiated in accordance with the shape of the diseased site. In the positioning work, while the position of a diseased site is being monitored by an X-ray image-capturing device, the angle adjustment for a treatment table is implemented in such a way that a particle beam is irradiated onto the diseased site along a direction determined at the stage of making a treatment plan; however, because this positioning work takes a long time, it is required to efficiently perform the positioning work.
In order to realize irradiation onto a patient fixed on the surface of a treatment bed from an arbitrary direction and with an arbitrary distance, especially, non-coplanar irradiation in which the irradiation direction is not perpendicular to the patient center axis, there has been proposed a radiation-therapy bed system (refer to Japanese Patent Application Laid-Open No. 1999-313900). In the radiation-therapy bed system, there are inputted patient position data (in an X-Y-Z coordinate system) and proton beam radiation angle, which are calculated when therapy simulation is performed; these data items (position and angle) are coordinate-transformed, as the X-direction, Y-direction, and Z-direction positions of the bed, the i-axis rotation angle (relative isocentric rotation), the p-axis rotation angle (pitching rotation), the r-axis rotation angle (rolling rotation), and the diseased-site position of a patient; the respective axes of the bed capture these transformed data items, as input position data items, and the respective axes are driven so that the patient diseased site is moved to a desirable position.
However, in the case where, while the diseased site or the like is being monitored by an X-ray image-capturing device, the i-axis, the p-axis, and the r-axis are adjusted, it is normally impossible to dispose the diseased site in such a way as to pass through the rotation center of each axis; therefore, the diseased site moves in the X-axis direction, Y-axis direction, or Z-axis direction, or in a direction obtained by combining these directions. As a result, in some cases, the diseased site falls outside the image capturing area of the X-ray image-capturing device; thus, in order to prevent the diseased site from falling outside the image capturing area, it is required to subtly adjust the X-axis, the Y-axis, and the Z-axis so that the position of the diseased site does not move.
In a conventional radiation-therapy bed system, there is provided six degrees of freedom in the driving axes, and by driving each axis, the diseased site of a patient can be moved to a desirable position; however, in the practical positioning work for the diseased site, it is required to subtly adjust the X-axis, the Y-axis, and the Z-axis, as described above. Therefore, there has been a problem that this adjustment work is extremely bothersome to the engineer or the like, and because the positioning work takes a long time, the throughput of the particle beam therapy system cannot be improved.